Commercial ice-making equipment typically produces clear ice cubes rather than clouded ice cubes. Clouded ice cubes are typically formed in domestic or residential ice makers found in refrigerators, and the like. These typical residential ice makers form ice cubes by depositing water into a mold attached to an evaporator or an ice tray and allowing the water to freeze in a sedentary state. Ice cubes formed in this manner are clouded because air and impurities become trapped in the water as it freezes. Clear ice-making machines, on the other hand, form ice by flowing water over a chilled surface. As the water flows over the chilled surface, layers of ice are formed without trapping air within the layers of ice.
In a typical commercial ice machine, water flows over a vertically disposed evaporator plate. The evaporator plate includes a plurality of pockets or cells in which ice cubes are formed. The ice cubes are harvested by heating the evaporator plate to a temperature sufficient to release the ice cubes from the cells. Such a system is disclosed, for example, in commonly-assigned U.S. Pat. No. 5,586,439 to Schlosser et al., which is incorporated by reference herein.
In most commercial clear ice systems, water is circulated through the system from a water reservoir by a water circulation pump. The water is pumped to a water distributor that distributes water across the evaporator plate or ice-forming mold. Unfrozen water flows down the face of the mold. A water curtain catches any water splash and unfrozen water is returned to a water reservoir. An ice thickness sensor detects the thickness of the ice forming on the mold. When a desired thickness is reached, the sensor signals the ice forming machine to terminate the freeze cycle and begin a harvest cycle.
One such commercial ice machine system is schematically illustrated in FIG. 1. A water supply plumbed to the machine provides water to a water sump 12. Water sump 12 is equipped with a level controller 14 and a drain line 16 is equipped with a solenoid dump valve 18. A water pump 20 circulates water from water sump 12 to a water distributor 22. Water from water distributor 22 is directed across an ice-forming mold 24. Water that does not freeze on a first pass over ice-forming mold 24 flows into the water sump 12. A water curtain 26 collects splashing water and also directs it into the water sump 12.
As shown in the schematic diagram of FIG. 1, a prior art water distributor 22 is essentially a tube-within-a-tube design. An interior tube 28, made from two separately molded parts, is positioned within an outer tube 30. Water pumped by water pump 20 flows into interior tube 28, which has a series of openings in a lower portion of the tube. From interior tube 28, water flows into the annular space between interior tube 28 and outer tube 30. Outer tube 30 also includes a series of openings in a lower portion of the tube through which the water flows onto ice-forming mold 24.
While water distributor 22 is effective in delivering a fairly uniform stream of water across the entire width of ice-forming mold 24, considerable water pressure is necessary to charge interior tube 28 with water for delivery to ice forming mold 24. Further, ice-making assemblies, such as that illustrated in FIG. 1, require periodic cleaning to ensure that the clear ice is not contaminated. Thorough cleaning of water distributor 22 requires that the water distributor be disassembled. While the disassembly steps of water distributor 22 are straightforward, reassembly can require careful alignment and proper placement of o-rings that seal the various sections inside the distributor. Also, a small brush must be used to clean holes through which water flows out of the inner and outer tubes. Further, the tubes are molded with a long central core, which is complicated and limits the lengths of the tubes. Thus, considerable time can be required to clean and complete the reassembly once the cleaning process is complete.
Non-tubular water distributors for clear ice making machines have been designed for delivering water to an ice-forming mold. For example, U.S. Pat. No. 6,148,621 to Byczynski et al., which is incorporated by the reference herein, describes one such non-tubular water distributor. This patent describes a water distributor that introduces water onto a floor containing a series of barriers. Water pumped into the water distributor flows over a rear edge of the floor and onto an ice-forming mold. The ice-making assembly described by Byczynski et al. is designed for a low volume ice making machine having a capacity of about 30 to about 50 pounds of ice per day. Such low volume systems do not have the water handling requirements of a large commercial system. While the water distributor described by Byczynski et al. is effective at delivering water to an ice-forming mold in a small system, it is inadequate to operate at low water pressure and still distribute water evenly across an ice-forming mold as used in an ice-making assembly for a larger commercial unit. Such large ice making machines, having an ice-forming mold with a width of 20 inches or more, typically have production capacities of about 200 to about 2500 pounds of ice per day. Furthermore, the water distributor needs to be easily disassembled and reassembled for cleaning and should present minimal resistance to water flow.